9621993985 has 4 divisors (see below), whose sum is σ = 11546392788. Its totient is φ = 7697595184.

The previous prime is 9621993959. The next prime is 9621993991. The reversal of 9621993985 is 5893991269.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5594441616 + 4027552369 = 74796^2 + 63463^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9621993985 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 962199394 + ... + 962199403.

It is an arithmetic number, because the mean of its divisors is an integer number (2886598197).

Almost surely, 2^9621993985 is an apocalyptic number.

It is an amenable number.

9621993985 is a deficient number, since it is larger than the sum of its proper divisors (1924398803).

9621993985 is a wasteful number, since it uses less digits than its factorization.

9621993985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1924398802.

The product of its digits is 9447840, while the sum is 61.

The square root of 9621993985 is about 98091.7630843691. The cubic root of 9621993985 is about 2126.9389627062.

The spelling of 9621993985 in words is "nine billion, six hundred twenty-one million, nine hundred ninety-three thousand, nine hundred eighty-five".